Silicon carbide (SiC) is expected to be a material for a next-generation semiconductor device. SiC has excellent physical properties, such as a triple the band gap, about ten times the breakdown field strength, and about triple the thermal conductivity of silicon (Si). By utilizing the characteristics, a semiconductor device that is low loss and capable of operating at high temperature can be implemented.
However, when a metal insulator semiconductor (MIS) structure is formed using SiC, the amount of interface state existing between a semiconductor and an insulating film is larger than Si. Consequently, charge mobility is reduced, and which causes a problem that on-resistance of a metal insulator semiconductor field effect transistor (MISFET) or an insulated gate bipolar transistor (IGBT) becomes high.